An update to the Team Fortress 2 Blog has word on back-end fixes underway: "We've got one more update to go out to our backend item system. After that, we'll be granting all the missing items that weren't granted properly when you finished achievements." In a far more substantial update, they announce that you can beta test the current incarnation of Team Fortress 2 bots that Valve is cooking up for the multiplayer shooter. They outline how you can test the bots in King of the Hill on koth_viaduct, koth_sawmill, and koth_nucleus, ad explain what to expect from your AI playmates:

TFBots are "players", and take up player slots. They run the exact same code that human players do, moving and firing weapons by pressing "virtual buttons". The bots have simulated humanlike senses, and only know what they see, hear, and touch. They also have realistic reaction times and aiming limitations. They don't "cheat" or use omniscient knowledge of the server state to make their decisions.